The aim of the study was to evaluate the effect of cryopreserved equine semen in the presence of trehalose-loaded liposomes on the integrity and function of sperm cells. Six ejaculations of five stallions collected with an artificial vagina were used. The ejaculates were diluted with INRA 96 ® 2:1 v/v and transported at 22 °C to the laboratory. Before cryopreservation, the semen was diluted with INRA Freeze ® to obtain the following treatments: T1) INRA Freeze ® (control), T2) INRA Freeze ® + liposomes, T3) INRA Freeze ® + liposomes+trehalose. Data were analysed using the Kruskal Wallis test. The percentages of sperm with intact DNA were 54.5, 57.9, and 64.8% for T1, T2 and T3, respectively (P>0.05). When evaluating the acrosomal and capacitation state after filtering with Percoll ® , the percentages of spermatozoa without acrosome reaction and without capacitation were 67.8, 79.2 and 68.1% in T1, T2, and T3, respectively (P>0.05), while the capacitated sperm without acrosome reaction and without capacitation was similar in T1 (47%) and T3 (32%) (P>0.05), and lower in T2 (16%) before filtering with Percoll ®. The use of liposomes and liposome-trehalose did not affect on the functional status and nuclear chromatin of the equine sperm after freezing, but it did affect the percentage of capacitated sperm without acrosome reaction after selecting the thawed semen using the Percoll ® gradient.

Fleas and ticks represent the two main groups of ectoparasites that infest companion animals. In particular, the flea Ctenocephalides felis felis and several members of the Rhipicephalus sanguineus complex are the main vectors of a wide range of pathogens on the American continent.

Background: Streptolysin O (SLO), a pore-forming protein in plasma membrane (PM), has been used to internalize a variety of molecules (DNA and RNA) in cells. In sperm, however, SLO has only been used to release acrosomal contents. Its possible use as biotechnology in the cryopreservation of pig semen. However, porcine sperm are very sensitive to the freeze-thaw process. The study aimed to evaluate the pore formation in the PM, the addition of trehalose and the post cryopreservation viability of porcine spermatozoa using SLO.Methods: Research period was spring 2017- summer 2018. Thirty ejaculates from five mature boars were used. Semen was incubated in SLO 0.6 IU/ml and trehalose (added at 100, 200 and 400 ìM). Semen diluted in commercial diluent as control group. Presence of pores was checked by scanning electronic microscopy. To evaluate sperm membrane integrity and functional status the Coomassie stain with HOST test and the Chlortetracycline test were used. Result: It was found that SLO could form pores in the sperm cell membrane The addiction of 200 ìM trehalose to the freezing medium have different effects on the quality of boar sperm, showing highest motility and viability during the cooling process.